Investigate and fight cyberattacks with SIFT Workstation

 

Digital forensics and incident response (DFIR) has hit a tipping point. No longer just for law enforcement solving cybercrimes, DFIR tools and practices are a necessary component of any organization’s cybersecurity. After all, attacks are increasing daily and getting more sophisticated – exposing millions of people’s personal data, hijacking systems around the world and shutting down numerous sites.

SANS has a smorgasbord of DFIR training, and we also offer a free Linux distribution for DFIR work. Our SANS Investigative Forensic Toolkit (SIFT) Workstation is a powerful collection of tools for examining forensic artifacts related to file system, registry, memory, and network investigations. It is also available bundled as a virtual machine (VM), and includes everything one needs to conduct any in-depth forensic investigation or response investigation.

Capture9The SIFT Workstation was developed by an international team of forensics experts, including entrepreneur, consultant and SANS Fellow Rob Lee, and is available to the digital forensics and incident response community as a public service. Just because it’s freely available and originally designed for training, though, doesn’t mean it can’t stand up to field investigations. The SIFT Workstation incorporates powerful, cutting-edge open-source tools that are frequently updated, vetted by the open source community and able to match any modern DFIR tool suite. Don’t just take our word for it. Thousands of individuals download SIFT yearly, and it’s used by tens of thousands of people all over the world, including those at multiple Fortune 500 companies. And recently, HackRead named SIFT Workstation in a list of the top 7 cyber forensic tools preferred by specialists and investigators around the world.

SIFT got its start in 2007, during the time SANS instructors were developing virtual machines (VMs) for use in the classroom. In its earliest iterations, it was available online as a download, but was hard-coded and static so whenever there were updates, users had to download a new version. By 2014, SIFT Workstation could be downloaded as an application series and was later updated to a very robust package based on Ubuntu. It can also be installed on Windows, if there is an Ubuntu subsystem running on the system.

In November 2017, SANS unveiled a new version of SIFT Workstation that allows for much more functionality, is much more stable, and is comprised of specific tools such as the Package Manager. This time the package supports rolling updates, and uses SALT, a Python-based configuration management platform, rather than a bootstrap executable and configuration tool.

The new version can work with more than 200 tools and plug-ins from third-parties, and newly added memory analysis functionality enables the SIFT Workstation to leverage data from other sources. New automation and configuration functions mean the user only has to type one command to download and configure SIFT. Because SIFT is scriptable, users can string together commands and create automated analysis, customizing the system to the needs of their investigation.

Download SIFT Workstation today, and get started on your own DFIR initatives. And look into our FOR508: Advanced Incident Response and Threat Hunting course for hands-on learning with SIFT, and how to detect breaches, identify compromised and affected systems, determine damage, contain incidents, and more.

Go Big with Bootcamp for Advanced Memory Forensics and Threat Detection

 

Many experienced security analysts end up repeating the same investigative playbook for similar types of cases day after day. They become technical experts but siloed into a single lane of investigative scenario, whether it be intellectual property theft, malware or intrusion investigations. With the rapid evolution of fileless malware and sophisticated anti-forensics mechanisms, security analysts need access to current system state that can be derived solely from memory analysis. Learning bleeding edge analysis skills such as memory interrogation can be a touch challenge requiring determined and extraordinary work. The relaunched bootcamp SANS FOR526 Advanced Memory Forensics and Threat Detection is the class that will get you and your team to this next level – it’s time for bootcamp!

Malware is more sophisticated, and its ability to evade detection growing. Cryptojacking – software programs and malware that hijack another’s computer without their knowledge to mine cryptocurrency – is one such example. Recently, researchers discovered a new cryptocurrency mining malware that employs multiple evasion techniques, including one that poses as an installer file for the Windows operating system so it seems less suspicious. And illicit cryptocurrency mining operations have increased dramatically over the past year, according to a recent Cyber Threat Alliance report, rising by as much as 459 percent in 2018.

The more complex, advanced malware and anti-analysis and evasion techniques pose great challenges to today’s security practitioners, as the endpoint detection methods and technologies, we rely upon to protect our enterprise fail. For this reason, we at SANS have decided to go big with a revised FOR526 course – with an additional boot camp – that teaches you how to isolate malicious activity using memory analysis to counter these evasions and allows you to determine the capability and intent of the intrusion for successful scoping and containment.

To move to proactive hunting, teams must have the skills to identify the activity for which there is no signature. The FOR526 course delivers this expertise with an intensive hands-on focus, allowing security practitioners to build on the knowledge advanced security professionals already have.

The two creators of FOR526, Alissa Torres and Jake Williams, understand the unique challenges of memory forensics and the complex types of cases examiners are up against today. Both forensics practitioners themselves, they know examiners need deeper technical expertise beyond just running a tool so they can perform memory analysis to understand the evidence, and that means offering students labs inspired by real-world investigations in which memory forensics saved the day. As Williams notes, “memory offers a very dense and target-rich search space for evidence of value. Memory-only malware? Malicious insiders using private browsing to eliminate disk evidence? Anti-forensics techniques? They all get stuck in memory.”

Williams and Torres have added a boot camp consisting of additional content and memory forensics challenges to make the course even more relevant for present-day memory forensics investigations and threat detection. The NEW FOR526: Advanced Memory Forensics and Threat Detection BootCamp brings you extended mid-week SANS NetWars challenges, more in-depth technical content and advanced threat detection scenarios to take senior incident responder professionals to the next level.

Slider_CTIAt this month’s Cyber Threat Intelligence Summit in Arlington, Virginia, Torres will run FOR526: Advanced Memory Forensics & Threat Detection January 23 – 28. The summit is a week-long conference and educational event with in-depth talks and interactive discussions, as well as community-building events, networking opportunities and hands-on, immersive courses designed to give you world-class training.

Learn more about the course new format and content by attending Alissa Torres webcast January 14th at 1:00 pm EST.

Register for the webcast: http://www.sans.org/u/Mi2

Next FOR526 course runs: http://www.sans.org/u/MhX

SANS FOR585 Q&A: Smartphone Forensics – Questions answered

 

 

Learning doesn’t stop when you leave the SANS classroom. Instructors Domenica “Lee” Crognale, Heather Mahalik and Terrance Maguire answer some of the most common questions from FOR585 Smartphone Forensics course students in these short videos:

1) Using Hashcat to Crack an Encrypted iTunes Backup: Acquiring a locked iOS can be difficult so an iTunes backup may be the best evidence to examine. The iTunes backup files might be encrypted so this mini webcast outlines how to use HashCat to crack the encrypted iTunes backup files.

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2) An Overview of Third Party App Examination: There are millions of applications (Apps) that can be used on a smartphone. This mini webcast outlines an approach to examining these applications.

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3) Why Every Examiner Needs a Test Device?: In a perfect world, we would always be examining rooted Androids and jailbroken iOS devices, but unfortunately, full access to the file system is becoming a thing of the past. This mini webcast highlights the importance of populating test devices with user data so you can better speak to the artifacts that you ARE able to access on your next examination.

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4)What if Nothing Supports Android Pie (v9)? The latest versions of Android are not commonly supported for acquisition by our tools. What can you do? Use ADB and interact with the live device. This mini webcast will teach you how to use ADB to extract information from Android devices and will discuss the traces some tools leave behind and why that trace is required if you want to obtain data.

 

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5) iOS Malware – Where to Begin: It’s notably more difficult to pinpoint malware on your non-jailbroken iOS device without access to the application packages. This mini webcast outlines some of the best practices in analyzing the files you can access to provide indications of suspicious activity and the applications and services that are likely responsible.

 

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6) Two Major Plists: This mini webcast will discuss how to determine if iMessage is disabled on an iPhone and how to determine if an iCloud restore occurred. Simple questions like this can make a difference in your investigation. We will discuss the file locations, which acquisition methods provide access to the files of interest and most importantly, how to parse the data.

 

 

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About SANS FOR585: Smartphone Forensics Course

This in-depth smartphone forensic course provides examiners and investigators with advanced skills to detect, decode, decrypt, and correctly interpret evidence recovered from mobile devices. The course features 27 hands-on labs, a forensic challenge, and a bonus take-home case that allow students to analyze different datasets from smart devices and leverage the best forensic tools, methods, and custom scripts to learn how smartphone data hide and can be easily misinterpreted by forensic tools. Each lab is designed to teach you a lesson that can be applied to other smartphones. You will gain experience with the different data formats on multiple platforms and learn how the data are stored and encoded on each type of smart device. The labs will open your eyes to what you are missing by relying 100% on your forensic tools. More information: http://sans.org/FOR585 | Next course runs: sans.org/u/Mht

More Resources:

mobile posterFOR585 Mobile Forensics Poster: Use this poster as a cheat-sheet to help you remember how to handle smartphones, where to obtain actionable intelligence, and how to recover and analyze data on the latest smartphones and tablets. This poster was created by FOR585 Advanced Smartphone Forensics course authors & Certified Instructors Heather Mahalik, Cindy Murphy and Domenica “Lee” Crognale with support from the SANS DFIR Faculty. Download it here

Heather Mahalik’s blog: https://smarterforensics.com/blog/

 

Shortcuts for Understanding Malicious Scripts

You are being exposed to malicious scripts in one form or another every day, whether it be in email, malicious documents, or malicious websites. Many malicious scripts at first glance appear to be impossible to understand. However, with a few tips and some simple utility scripts, you can deobfuscate them in just a few minutes.

Capture3SANS Instructor Evan Dygert conducted a webcast on October 3rd, 2018. This webcast teaches you how to cut through the obfuscation techniques the script authors use and not spend a lot of time doing it. Evan also demonstrates how to quickly deobfuscate a variety of malicious scripts.

The samples of the scripts he provided during the webcast can be downloaded here: https://dfir.to/MaliciousScripts. Please note the password for the samples.zip folder is: “infected”

 

 

Capture4We hope that the techniques presented in this webcast help you to begin deobfuscating potentially malicious JavaScript.  This topic is explored in depth in the SANS FOR610: Reverse-Engineering Malware: Malware Analysis Tools and Techniques course.  This class offers an excellent opportunity to understand the unique and insightful perspective that malware analysis can bring to your investigations.

 

 

 

New CheatSheets you might be interested in:

Tips for Reverse-Engineering Malicious Code – This cheat sheet outlines tips for reversing malicious Windows executables via static and dynamic code analysis with the help of a debugger and a disassembler. Download Here

REMnux Usage Tips for Malware Analysis on Linux – This cheat sheet outlines the tools and commands for analyzing malicious software on the REMnux Linux distribution Download Here

Cheat Sheet for Analyzing Malicious Documents – This cheat sheet presents tips for analyzing and reverse-engineering malware. It outlines the steps for performing behavioral and code-level analysis of malicious software. Download Here

Malware Analysis and Reverse-Engineering Cheat Sheet – This cheat sheet outlines tips and tools for analyzing malicious documents, such as Microsoft Office, RTF and Adobe Acrobat (PDF) files Download Here

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For opportunities to take the FOR610 course, consider upcoming runs and modalities: 

US & International live training : Live events offered throughout the US, EMEA & APAC regions.

 DFIR Summits :  Two days of industry expert talks plus DFIR training events

Simulcast :   Live events from anywhere in the world.

OnDemand  : Learn at your own pace, anytime, anywhere.

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DFIR Resources: Digital Forensic Blog | Twitter | Facebook | Google+ | Community Listservice | DFIR Newsletter

Inhibiting Malicious Macros by Blocking Risky API Calls

 

Microsoft Office Macros have been the bane of security analysts’ lives since the late 1990s. Their flexibility and functionality make them ideal for malware authors to use as a primary stage payload delivery mechanism, and to date the challenge they pose remains unsolved. Many organisations refrain from blocking them completely due to the impact it would cause to their users, and instead rely on a combination of detection and mitigation technology to compensate for the risk they pose.

I have long thought that it would be ideal if Microsoft were able to implement granular controls via group policy over which activities macros were permitted to perform, for example allowing the blocking of process execution or network activity. In the interim, I have been experimenting with alternative methods to limit which functions a macro can call, either by redefining or patching the high risk API calls to prevent their intended outcome.

Below we can see a very basic example of what a malicious macro might look like. The fact that the subroutine is named “AutoOpen” means that it will be run as soon as the document is opened (and if required, macros are enabled).  The command “Shell” at the beginning of the line instructs Word to execute the process as specified in the parameter, so in this case the macro will launch the Windows calculator.

 

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Option 1 – Using global templates to override built-in functions

Shell is the function built into VBA which is used to launch new processes, and as such, can often be found in malicious macros. Malware authors leveraging macros as a primary stage payload typically want to either download or drop a file, and then execute it. Alternatively, they could decide to execute an existing process on the system, such as powershell, with parameters which will take actions against their intended target. Common to both of these methods is the requirement for something to be run, and this is where Shell comes in. If we were able to somehow disable the Shell function, then we might be able to prevent the malicious macro from succeeding in it’s goal.

The first experiment involved redefining the Shell function, with the hope that the newly defined function would override the built-in one. We can achieve this by placing the code in the global template which is named normal.dotm or within an add-in (which is effectively a template that is loaded every time Word is opened), either way, our code will become part of the malicious macros execution.

Below we can see the redefined function used as part of this experiment. This was saved within normal.dotm (the global template), with the intention that when Shell was called, rather than calling the system function to launch the process, our redefined function would be called, resulting in a popup warning the user that the activity had been blocked.

 

ss_normal_dot_macro

 

Then, using the one line test macro that attempts to execute ‘cmd.exe /c calc.exe’, we can see that the redefined function worked well and blocked the execution of the process. Unfortunately, it only seemed to work when the malicious code was placed within the document and not when it was within a seperate module. The reason for this is unknown and warrants further research, as if solved, this would be the easiest way to achieve our goal.

 

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Option 2 – Patching associated API in VBE7.dll to alter behaviour

For a more surgical approach we can look at API hooking the dll which is leveraged when macro code is executed. Looking through the dlls, which are loaded into Word at runtime, we can observe that VBE7.dll includes a large number of exports that appear related to the execution of macro code. Below we can see a snapshot from the list of exports with one in particular highlighted, rtcShell, that warranted further investigation.

 

ss_vbe_exports

 

Digging into this function we can see that it’s nothing more than a small wrapper around the CreateProcess Windows API call. The particular code block which executes the process is listed below. Looking at the parameters being passed to the API,  we can see that the EBX register is being used to hold a pointer to the name of the process to be executed.

 

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At this point, if we want to alter the way the process is launched we can patch the instructions to alter the process creation flags, which is one of the parameters passed to the CreateProcess API. Alternatively, we could completely patch out the API call to prevent the execution from occurring.

In this case we are going to leverage the CREATE_SUSPENDED process creation flag to allow the process to launch, but immediately be frozen into a suspended state, preventing the code from running.

 

ss_msdn_createsuspended

 

The patch sets the ECX register to 4, which is the numeric value of CREATE_SUSPENDED, and then this is pushed as the creation flags parameter to the CreateProcess API call, resulting in the process being instructed to launch in a suspended state.

 

ss_ida_postpatch

 

Following this patch, a test macro that was designed to launch powershell was executed, and as we can see from the process explorer window, it was placed into a suspended state, thus mitigating any impact and allowing an opportunity for endpoint protection sensors to scan and identify any threatening behaviour.

 

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These are just proof of concepts, and would require more research and work before they were used in a production environment. I still believe that the ideal state would be for Microsoft to implement more granular security controls against macros, allowing organisations to continue using them, but at the same time empowering them with the ability to limit their capabilities depending on individual risk appetites.

 

Any comments or feedback would be very welcome!

 

-Adam (Twitter: @CyberKramer)

Top 11 Reasons Why You Should NOT Miss the SANS DFIR Summit and Training this Year

The SANS DFIR Summit and Training 2018 is turning 11! The 2018 event marks 11 years since SANS started what is today the digital forensics and incident response event of the year, attended by forensicators time after time. Join us and enjoy the latest in-depth presentations from influential DFIR experts and the opportunity to take an array of hands-on SANS DFIR courses. You can also earn CPE credits and get the opportunity to win coveted DFIR course coins!

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To commemorate the 11th annual DFIR Summit and Training 2018, here are 11 reasons why you should NOT miss the Summit this year:

1.     Save money! There are two ways to save on your DFIR Summit & Training registration (offers cannot be combined):

·       Register for a DFIR course by May 7 and get 50% off a Summit seat (discount automatically applied at registration), or

·       Pay by April 19 and save $400 on any 4-day or 6-day course, or up to $200 off of the Summit. Enter code “EarlyBird18” when registering.

2.     Check out our jam-packed DFIR Summit agenda!

·       The two-day Summit will kick off with a keynote presentation by Kim Zetter, an award-winning journalist who has provided the industry with the most in-depth and important investigative reporting on information security topics. Her research on such topical issues as Stuxnet and election security has brought critical technical issues to the public in a way that clearly shows why we must continue to push the security industry forward.

·       The Summit agenda will also include a presentation about the Shadow Brokers, the group that allegedly leaked National Security Agency cyber tools, leading to some of the most significant cybersecurity incidents of 2017. Jake Williams and Matt Suiche, who were among those targeted by the Shadow Brokers, will cover the history of the group and the implications of its actions.

·       All DFIR Summit speakers are industry experts who practice digital forensics, incident response, and threat hunting in their daily jobs. The Summit Advisory Board handpicked these professionals to provide you with highly technical presentations that will give you a brand-new perspective of how the industry is evolving to fight against even the toughest of adversaries. But don’t take our word for it, have a sneak peek, check out some of the past DFIR Summit talks.

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Immerse yourself in six days of the best in SANS DFIR training. Here are the courses you can choose from:

·       FOR500 – Advanced Windows Forensics

·       FOR585 – Advanced Smartphone Forensics

·       FOR610 – Reverse-Engineering Malware

·       FOR508 – Digital Forensics, Incident Response & Threat Hunting

·       FOR572 – Advanced Network Forensics: Threat Hunting, Analysis, and Incident Response

·       FOR578 – Cyber Threat Intelligence

·       FOR526 – Memory Forensics In-Depth

·       FOR518 – Mac and iOS Forensic Analysis and Incident Response

·       MGT517 – Managing Security Operations: Detection, Response, and Intelligence

3.    All courses will be taught by SANS’s best DFIR instructors. Stay tuned for more information on the courses we’re offering at the conference in a future article post.

4.     Rub elbows and network with DFIR pros at evening events, including networking gatherings and receptions. On the first night of the Summit, we’re going to gather at one of Austin’s newest entertainment venues, SPiN, a ping pong restaurant and bar featuring 14 ping pong tables, lounges, great food, and drinks. Give your overloaded brain a break after class and join us at our SANS Community Night, Monday, June 9 at Speakeasy. We will have plenty of snacks and drinks to give you the opportunity to network with fellow students.

5.     Staying to take a DFIR course after the two-day Summit? Attend SANS@Night talks guaranteed to enrich your DFIR training experience with us. Want to know about threat detection on the cheap and other topics? As for cheap (and in this case, that doesn’t mean weak), there are actions you can take now to make threat detection more effective without breaking the bank. Attend this SANS@Night talk on Sunday evening to learn some baselines you should be measuring against and how to gain visibility into high-value actionable events that occur on your systems and networks.

6.     Celebrate this year’s Ken Johnson Scholarship Recipient, who will be announced at the Summit. This scholarship was created by the SANS Institute and KPMG LLP in honor of Ken Johnson, who passed away in 2016. Early in Ken’s digital forensics career, he submitted to a Call for Presentations and was accepted to present his findings at the 2012 SANS DFIR Summit. His networking at the Summit led to his job with KPMG.

7.     Prove you’ve mastered the DFIR arts by playing in the DFIR NetWars – Coin Slayer Tournament. Created by popular demand, this tournament will give you the chance to leave Austin with a motherlode of DFIR coinage! To win the new course coins, you must answer all questions correctly from all four levels of one or more of the six DFIR Domains: Windows Forensics & Incident Response, Smartphone Analysis, Mac Forensics, Memory Forensics, Advanced Network Forensics, and Malware Analysis. Take your pick or win them all!

 

8.     Enjoy updated DFIR NetWars levels with new challenges. See them first at the Summit! But not to worry, you will have the opportunity to train before the tournament. You’ll have access to a lot of updated posters that can serve as cheat sheets to help you conquer the new challenges, as well as the famous SIFT WorkStation that will arm you with the most powerful DFIR open-source tools available. You could also choose to do an hour of crash training on how to use some of our Summit sponsors’ tools prior to the tournament. That should help give you an edge, right? That new DFIR NetWars coin is as good as won!

9. The Forensic 4:cast Awards winners will be announced at the Summit. Help us text2985celebrate the achievements of digital forensic investigators around the world deemed worthy of the award by their peers. There is still time to cast your vote. (You may only submit one set of votes; any additional voting will be discounted). Voting will close at the end of the day on May 25, 2018.

10.  Come see the latest in tools offered by DFIR solution providers. Summit sponsors and exhibitors will showcase everything from managed services covering advanced threat detection, proactive threat hunting, and accredited incident response to tools that deliver rapid threat detection at scale, and reports that provide insights for identifying potential threats before they cause damage.

11.  Last but not least, who doesn’t want to go to Austin?!? When you think Austin, you think BBQ, right? This city isn’t just BBQ, Austin has amazing food everywhere and there’s no place like it when it comes to having a great time. The nightlife and music include the famous 6th Street – which, by the way, is just walking distance from the Summit venue. There are many other landmarks such as Red River, the Warehouse District, Downtown, and the Market District. You will find entertainment of all kinds no matter what you’re up for. Nothing wrong with some well-deserved play after days full of DFIR training, lectures, and networking!

As you can see, this is an event you do not want to miss! The SANS DFIR Summit and Training 2018 will be held at the Hilton Austin. The event features two days of in-depth digital forensics and incident response talks, nine SANS DFIR courses, two nights of DFIR NetWars, evening events, and SANS@Night talks.

The Summit will be held on June 7-8, and the training courses run from June 9-14.

We hope to see you there!

Automated Hunting of Software Update Supply Chain Attacks

 

Software that automatically updates itself presents an attack surface, which can be leveraged en masse through the compromise of the vendor’s infrastructure. This has been seen multiple times during 2017, with high profile examples including NotPetya and CCleaner.

Most large organisations have built robust perimeter defences for incoming and outgoing traffic, but this threat vector is slightly different and far more difficult to detect. Update packages are often deployed in compressed, encrypted or proprietary formats and would not easily be subject to an antivirus scan or sandbox analysis during transit. This leaves us with a large number of trusted processes within our infrastructure that could turn on us at any time and download something evil, which could potentially be undetectable by endpoint antivirus software.

It would be almost impossible to detect all potential malicious code changes, as they could be as simple as changing a single assembly instruction from JNZ to JZ to allow for unauthorised access or privilege escalation to occur. However, this doesn’t prevent some additional proportionate due diligence on the update package being pulled down and installed.

 

Methodology for discovering inbound evil updates

1. Discover all the software across your estate that could be auto updating
Let us consider for a moment software that automatically updates, and how it looks on the endpoint. Firstly, it needs to open an internet connection to a server that will allow it to identify whether the version currently running is up to date, or whether there is a newer version available. This may occur when the process is first executed or at intervals (set dates or times or even randomly). If the version is current then it will try again later, mostly likely connecting to the same server and repeating the process of checking the version numbers. The traffic volume on each occasion is likely to be very small, after all, all that it needs to ask is “what is the current version number?” and the reply need only be “1.0.32” or similar.

If we put these components together we can build a search for a process, other than a browser (to reduce the noise), which makes repetitive connections to the same server on multiple occasions. We can further refine by looking for low volume traffic in the transmissions. This data may contain false positives such as the checking of licence validation, however this doesn’t matter as we will refine this further in the next stages.
2. Monitor traffic ratios for evidence of updates being downloaded
Once we have a list of processes, devices and servers that have displayed the behaviour from our discovery phase, we can now monitor the traffic volume ratios for abnormal behaviour. Consider a process that had been polling the same server with 5KB uploads followed by 50KB downloads for the past month when suddenly the volume of the download changes to 300MB. It would be a clear outlier based on volumes and upload/download ratios.
3. Perform automated sandbox analysis on detected binaries post update
Now we’re looking for a suspicious update, not just any update, so we can send the installer from the endpoint to an internal sandbox for analysis. Alternatively, we could trigger the same update to occur within a sandbox running our gold image. The sandbox would perform a behavioural analysis, which we would use to highlight any suspicious behaviour during, or after the update process takes place.
4. Alert CERT for further examination should there be evidence of anything suspicious
This can then feed the alerting system used by our SOC/CERT for a manual review and prompt containment activity should the updates contain malware – at this point the number of machines that have pulled the update should be small and we can prevent further infections through proxy blocks etc.

 

Demonstration of concept

Here we will demonstrate the concept by conducting a deep dive into the behavior of the Notepad++ update process. We begin by identifying the polling between the process and update server. We can see from Process Monitor below that the traffic volumes are low, and the upload / download ratio is relatively similar, approximately 1:11 when there is no update to be downloaded.

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Now let’s have a look at what happens when there is an update available.

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We can see the difference when there is an update to be pulled, in this case the download volume is significantly higher than the upload as we would expect, in fact it’s over 673 times higher at 1:7756.

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In addition, following the network activity we can see that a process launch has been identified. This is the start of the update installation and provides us details on the location of the update binary.  At this point we can take the desired action to review the file, this may include a local scan or better yet, uploading the binary to an internal sandbox for behavioural analysis to take place – this would give us the added benefit of detecting a threat before the antivirus signatures are available.

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Practicalities and further ideas

In a large network there is going to be a lot of noise and you may want to select the top 50 auto updating processes that are most widely utilised across the estate and focus on them. This way you can be more selective about the alerts that go to your SOC.

Some processes may update on the fly using hot patching, in which case better results would be obtained from the creation of a custom image for your sandbox with all of these processes installed, so there would be no need to send/pull binaries and you could monitor the entirety of the update process taking place, including all files dropped to disk and executed during the update.

Feedback and ideas are always welcome!

Happy hunting

-Adam (Twitter: @CyberKramer)

Acquiring a Memory Dump from Fleeting Malware

Introduction

The acquisition of process memory during behavioural analysis of malware can provide quick and detailed insight. Examples of where it can be really useful include packed malware, which may be in a more accessible state while running, and malware, which receives live configuration updates from the internet and stores them in memory. Unfortunately the execution of some samples can be transient and the processes will be long gone before the analyst has a chance to fire up ProcDump. A while back, HBGary released a nifty tool called Flypaper, which prevented a process from closing down, allowing more time for the memory to be grabbed, but unfortunately the tool is now difficult to find and awkward to use. I’ve spent some time considering a suitable alternative that would work on the latest versions of Windows.

A little known feature…

During my research I found an article detailing a little known feature in Windows entitled ‘Monitoring Silent Process Exit‘.

TL;DR – You can configure Windows to automatically generate a memory dump when a process with a specified name exits.

So what this means for us is, even though the malware finishes running very quickly, we can obtain a full memory dump and extract what we need from it at our leisure.

This feature is designed as part of the Windows debugging portfolio, but we can use it as a tool in our belt. The easiest way to configure is by using a Microsoft tool named gflags.exe, which is easy to download and use. The screenshot below shows the configuration that I’ve had success with. You provide the name of the executable you’re interested in keeping an eye on (it doesn’t matter from where the process is run). In addition you have the option to choose what kind of memory dump you want generating, Custom Dump Type 2 represents MiniDumpWithFullMemory, which I found to give the most comprehensive output. There are plenty of other options that can be found on MSDN. Then you just need to run the process and wait for it to finish.

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Testing the concept

To test the concept I wrote a tiny program, shown below, designed to load a string to memory and have the process exit very quickly – certainly before we would have a change to pull the string from live memory.

int main()
{
char secretString[] = “This is a secret string!”;
return 0;
}

I compiled, executed and the mini dump appeared in the appropriate folder. A quick check with BinText showed the secret string that had been stored in memory.

bintext_screenshot

This is all instigated through a small number of registry entries, details of which are listed in the Microsoft article on the subject, and could easily be implemented into a sandbox or endpoint security setup to gather clues about what has occurred. I’ve found this to be a neat alternative to Flypaper without having to go to the trouble of writing a hook for the ExitProcess function.

Happy analysing!

-Adam (Twitter: @CyberKramer)

Uncovering Targeted Web-Based Malware Through Shapeshifting

Targeted Web-Based Malware?

Malware authors are frequently observed leveraging server side scripting on their infrastructure to evade detection and better target their attacks. This includes both exploit kits and servers hosting secondary stage payloads, all of which can easily be set up to alter their responses based on the footprint of the visitor. This could include geolocation of the IP address visiting the site if the attacker is targeting users from a particular country or region, or perhaps user-agent if they are only focused on certain browsers or operating systems. Without access to the source code leveraged on the server, it is difficult to detect whether it would alter its behaviour if you were visiting from a different device or location, and therefore malware analysts may find themselves declaring a link benign, or that the payload server is down, when in fact, it is only presenting that way to the analyst in question.

Got an example?

An example of this can be seen in the Malwarebytes blog on Magnitude exploit kit which details that  “…users are inspected at a ‘gate’ that decides whether or not they should be allowed to proceed to Magnitude EK. This gate, which has been nicknamed ‘Magnigate’ by Proofpoint, performs additional checks on the visitor’s IP address and user-agent to determine their geolocation, Internet Service Provider, Operating System and browser information…”

Hmm, so what can I do?

There is of course a balance here, even if you have access to VPN software, which allows you to select the country you want to appear from, it would be extremely time consuming and cumbersome to iterate through all of the available countries, each time using different browsers and painstakingly looking to identify whether there was any variation in the responses.

To aid in this task, I have written a new tool which automates this whole process and may be useful during malware analysis if you suspect the server is hiding something from you.

It works as follows –

  1. Loads a list of countries and user-agents that you want to appear from
  2. Leverages a proxy listing website’s API to obtain various country proxies
  3. Verifies that the proxies are working, and that the geolocation is per requirements
  4. Connects to the server using the proxy and iterates through all of the user-agents requesting the site multiple times
  5. Identifies any results which are different from the control value and highlights to the analyst

Demonstration

I’ve uploaded a number of test documents to my webserver, which you are welcome to use for your testing:

adamkramer.uk/browser-test.php & adamkramer.uk/browser-test-404.php

Both of these do the same thing – they wait until they observe someone connecting from a Chinese IP address with an iPhone user-agent before presenting the main content. The first URL will return a result in all other circumstances stating “Go away”, and the second will return a 404 error unless the conditions are met.

404_script_screenshot

The screenshot below shows the script iterating through various user-agents whilst connected to a Chinese proxy. In each case we can see the result was a 404 until the iPhone user-agent was sent, after which the script presented a ‘diff’ style output on what was different about this case.

China-iPhone

Great! Where can I get it?

The script was written in Python (v3.x) and is available from Github here.

Please feel free to use / fork / enhance / provide feedback.

 

Happy analysing!

-Adam (Twitter: @CyberKramer)

 

Coin Check: Win the challenge, join the elite list of lethal forensicators & take home a brand new DFIR challenge coin!

forensics_coin (1)Hundreds of SANS Institute digital forensics students have stepped up to the challenge and conquered. They’ve mastered the concepts and skills, beat out their classmates, and proven their prowess. These are the elite, the recipients of the SANS Lethal Forensicator Coin, an award given to a select portion of the thousands of students that have taken any of the SANS Institute Digital Forensics or Incident Response (DFIR) courses. Now, the institute is expanding the opportunity for students to earn these highly coveted tokens in each of the SANS DFIR courses.

Thanks to an effort led by curriculum lead Rob Lee & the SANS DFIR faculty, students can now win specific SANS Lethal Forensicator Coins designed to go with each of the DFIR course themes. These coins are tailored to be icons and the precious prizes to be won by students as a proof and symbol of their mastery in a specific digital forensics specialty.

New DFIR course challenge coins available now:

500FOR500: Windows Forensic Analysis

“Ex Umbra in Solem”: From the Shadows into the Light
In today’s digital world, forensics plays a critical role in uncovering the truth. Forensic examiners shine light on the facts of the case, making good decisions possible. And the forces of evil unceasingly develop new ways to hide their activities, forcing us to continually improve our skills to counter them.

508FOR508: Advanced Digital Forensics, Incident Response & Threat Hunting

“Non Potestis Celare”: You  cannot hide
The most successful incident response teams are evolving rapidly due to near-daily interaction with adversaries. New tools and techniques are being developed, providing better visibility and making the network more defensible. Adversaries can no longer hide.

610FOR610: Reverse-Engineering Malware

“R.E.M”: Reverse-Engineering Master

Today,  attackers are modifying their malware with increasing frequency to bypass antivirus and other endpoint controls. Through reverse-engineering Malware (R.E.M) Analysis Masters can isolate the most appropriate Indicators of Compromise (IOCs) to stop & identify malware.

585FOR585: Advanced Smartphone Forensics

“Omnis Tactus Vestigium Relinquit”:  Every contact leaves a trace
Knowing how to recover all of the data residing on the smartphone is now an expectation in the digital forensics field, and examiners must understand the fundamentals of smartphone handling, data recovery, accessing locked devices, and manually recovering data hiding in the background on the device. There are traces of evidence hiding on the device, and you know how to uncover them.

572FOR572: Advanced Network Forensics Analysis

“Malum Loquitur, Bonum Auscultat”: Evil must talk, so good must listen

Network Forensic professionals are hunters with great visibility, who can find a target among a mass of camouflaging data. Wisdom, experience, and stealth are all embodied by the owl’s watchful, unwavering eye, seeking its prey under the cover of darkness. No matter how crafty an adversary may be, their communications will allow the hunter to find, identify, and ultimately eliminate their presence.

518FOR518: Mac Forensics

“Impera magis. Aliter cogita”: Command more and think differently.

Apple users have always thought differently and that goes for Apple forensicators too. The analysts who hold this coin take command of their forensic analysis and appreciate looking at the raw data and interpreting it correctly without the necessity of superfluous tools. Knowing where you came from can help you move forward, this is where the hat tip to the original colored Apple logo comes in. New artifacts are presented to analysts in every OS update, the knowledge of historic elements may provide insight.

FOR578_coinFOR578: Cyber Threat Intelligence

“Hominem unius libri timeo”: I fear the man of one book.

FOR578 is all about developing analytical skills. To think critically and expand our views which is a skill that applies to any security profession. The quote is attributed to Thomas Aquinas and despite the common use of the phrase (which is meant to deride the person who is not well studied across multiple subjects) the original meaning was to state that a person who understood one good book well could defeat their opponent. Thus, this phrase can be interpreted two entirely different ways. Both are about self-education and broadening our views on the world.

FOR526_coinFOR526: Memory Forensics In-Depth

“Cur mihi oculi dolent?” Why do my eyes hurt?

Memory forensics reveals deeper insights into the state of a compromised system and stands as the best source for detection of malware and OS/process manipulation/subversion. These analysis methods reveal key evidence which may not be uncovered through querying the operating system or digging through network packets. This quote comes from the original Matrix movie, a question Neo asks of Morpheus when he first wakes from his life in the artificial reality created by sentient machines. It is this awakening and raw view of reality that we as forensic examiners/incident responders strive to achieve through deeper analysis of system memory.

 

Netwars DFIR Netwars

Staying up-to-date with the latest challenges in the digital forensics field demand analytical skills that cannot be gained by just reading a textbook. Just like firemen could never learn the skills of how to fight a fire by just studying theory, incident responders, threat hunters, and digital forensic investigators can test their skills with DFIR Netwars.

New DFIR Challenge coin back design:

BackThe challenges for each course are held on the last day. Students must successfully overcome a number of obstacles, directly compete against fellow students, and prove their proficiency during timed, hands-on incidents. The obstacles, competitions and hands-on scenarios have been created by SANS’ top instructors – digital forensics practitioners, subject matter experts, experienced teachers and professional leaders in their own right. At the end of the challenge, the instructor announces the winner(s) who are awarded the coins at the end of the 6th day of class and winners are later on listed on the SANS Institute’s virtual wall of Lethal Forensicator Coin Holders.

 

History of the SANS Challenge coins:

The coin – more precisely, Round Metal Object (RMO) – was initially created to recognize students who demonstrate exceptional talent, contributions, or who serve as leaders in the digital forensics profession and community. The coin is meant to be an honor; it is also intended to be rare. SANS Institute uses the coins to identify and honor those who excel at detecting and eradicating threats, understand the critical importance of cybersecurity and continually strive to further not only their knowledge but also the knowledge of the entire digital forensics field. They actively share their experience and encourage learning through participation in the community and are typically leaders in the digital forensics and incident response community.

Those who are awarded the Lethal Forensicator are also bestowed special privileges and recognition, including participation in the so-called and well-regarded “coin check” challenge and response.

“Coin check” Challenge:

Initiated by one coin holder to another, a coin check typically begins by a challenger holding his or her coin in the air or slamming it on a table and yelling “coin check!” All who are challenged must respond by showing their coins to the challenger within 10 seconds, and whoever fails to do so must buy everyone a round of drinks. If all the challenged coin holders do produce their coin, the challenger must by the round of drinks. (By the way, if you accidentally drop your coin and it makes an audible sound on impact, then you’ve “accidentally” initiated a coin check. And, there are no exceptions to the rules!)

Coin checks aside, there are other ways to win the DFIR Challenge coins besides being an exceptional DFIR student and winning the classroom challenges. Each GOLD GCFA, GREM, GCFE member that has written a published white paper that has furthered the field of research in the Digital Forensics field receives a coin, as do SANS Digital Forensics Blog authors who have written six published entries over a one-year span. In addition, speakers and panelists who participate at a SANS Digital Forensic Summit are awarded coins (vendors and vendor-related speakers are not eligible). Finally, any coin holder can nominate an individual in the digital forensics field who has contributed knowledge, tools or service.

For more information on our SANS DFIR courses, please visit our Forensics Courses list. And to read more about the coin and the history of the term “Forensicator,” check out our Community – Lethal Forensicator Coin page.